Anchor having pivotable flukes



United States Patent ANCHOR HAVING PIVOTABLE FLUKES 8 Claims, 10 Drawing Figs.

[1.5. CI 114/208 int. Cl B63! 21/44 Field at Search 1 14/208,

[56] References Cited UNITED STATES PATENTS 2,987,028 6/196! Fair 114/208 3,306,248 2/l967 Austin 1 14/208 Primary ExaminerTrygve M. Blix Attorney-Rogers, Bereskin and Parr ABSTRACT: An anchor having a stock and a pair of planar flukes diverging from the stock. The inner opposing edges of the flukes bear digging plates which widen towards the base of the anchor and are connected together at the anchor base by slide plates to form a box structure through which the stock passes. The bottom of this box is closed by a jack plate which extends laterally beyond the digging plates. When the anchor drags along a soft bottom, dirt fills the box base, and also accumulates in the exterior angle between the lower digging plate and jack plate, tilting the flukes down to bury the anchor.

Patented Sept. 22, 1970 3,529,563

INVENTOR. HENRY FAST Patented Sept. 22, 1970 3,529,563

INVENTOR. H E N RY FAST ANCHOR HAVING PIVOTABLE FLUKES This invention relates to an anchor for watercraft.

Many types and varieties of anchors have been designed in the past to grip the bottom beneath a body of water and prevent a boat to which it is connected from drifting. Such anchors have operated with varying degrees of effectiveness, but generally they have tended to plough along the bottom (he. be dragged along the bottom) for a substantial distance before burying themselves sufficiently to hold the boat. Ac cordingly, it is an object of the present invention to provide an anchor that can be made light in weight and which will very quickly bury itself in a relatively soft bottom and provide relatively good holding power in a rocky bottom. This is achieved by providing an anchor comprising:

a. a stock;

b. a pair of flukes comprising;

i. a pair of digging plates having base portions fixed to said stock and extending from said stock in a common plane with said stock, said digging plates having pointed tips;

ii. a pair of flanges extending along opposed inside edges of said digging plates at right angles thereto, said flanges having enlarged bases and tapering towards said tips of said digging plates to define pointed tips for said flukes;

c. a pair of side plates joining the bases of said flanges to form a box structure having an open end facing the tips of said flukes, said stock extending through said box structure;

d. a shank pivotally connected to said stock at a location within said box structure and protruding from said box structure in a direction towards the tips of said flukes; and

e. a base plate closing the end of said box structure opposite said open end, said base plate having protruding portions extending substantially beyond said side plates;

so that when said anchor is dragged along a relatively soft bottom, dirt will collect between a said side plate and the protruding portion of said base plate adjacent said side plate and will tilt the tips of said flukes downwardly to bury said anchor.

Further objects and advantages of the invention will appear from the following disclosure, taken together with the accompanying drawings, in which:

FIG. I is a perspective view of an anchor according to the invention, looking towards the base of the anchor:

FIG. 2 is a perspective view of the anchor of FIG. I looking from above and slightly to one side;

FIG. 3 is a plan view ofa digger plate for the anchor of FIG.

FIG. 4 is a plan view of a flange for the anchor of FIG. 1',

FIG. 5 is a plan view of a side plate for the anchor of FIG. 1;

FIG. 6 is a perspective view of a bushing for the anchor of FIG. I;

FIG. 7 is a plan view of a base plate for the anchor of FIG. 1',

FIG. 8 is a side view of the base plate of FIG. 7 and with a portion of a side plate in position thereon;

FIG. 9 is a side view of the anchor of FIG. I resting on a bottom beneath a body of water; and

F IG. I0 is a side view showing the anchor buried in the bot-- tom.

Referring to the drawings, there is shown an anchor having a tubular stock 2 to which is secured a pair of flukes generally indicated at 4. Each fluke includes a digging plate 6 (shown alone in FIG. 3) having an enlarged end 8 connected to the stock 2, and tapering to a pointed tip 10. The fluke further ineludes flanges 12 extending along opposed inside edges of the digging plates 6, the flanges being oriented at right angles to the digging plates. The flanges 12 (one of which is shown by itself in FIG. 4) are longer than the digging plates, and dotted line 14 in FIG. 3 indicates the common line between each digging plate and its associated flange. The dotted line 14 terminates at a hole 16 through which the stock 2 passes. The digging plate 6, flanges l2 and stock 2 are connected together by welding.

It will be noted that each flange 12 has an enlarged base 18 (FIG. 4), terminating in a curved end 20, and tapers progressively along its length from the end 20, to a pointed tip 22. The lateral dimension d1 of each flange 12 at its base is approximately the same as the width ((2 of each digging plate 6 at its base, for a reason to be explazncd. Typical dimensions for .1 l3*/& pound anchor made according to the invention are given in Table 1 at the end of the description.

The sides of the bases of the flanges I2 are connected together by side plates 22 (one of which is shown alone in FIG. 5) welded thereto. The lines of contact between the flanges l2 and the side plates 22 are indicated by dotted lines 24 in FIG. 5. The two side plates 22 and two flanges 12 together form a box structure at the base of the anchor, with the stock 2 passing through this box structure.

One end of the box structure at the base of the anchor is open, and from it protrudes a shank 26 (FIG. 2). The shank 26 includes a bushing 28 (shown by itself in FIG. 6) rotatably mounted on the stock 2 between the side plates 22, and a shaft 30 welded to the bushing 28. A ring 32 is welded to the tip of the shaft 30 to accommodate an anchor line 34.

The bottom end of the box structure at the base of the anchor is closed by a base plate 36, shown in plan view in FIG. 7 and in edge view in FIG. 8. In FIG. 7, dotted lines 38 indicate the lines along which the base plate is welded to side plates 22, and dotted lines 40 indicate the lines along which the base plate is welded to the flanges 12. It will be observed that base plate 36 includes two protruding portions 42 each of which extends substantially beyond the side plates 22. Typically, the distance d9 by which the protruding portions 42 extend beyond the side plates 22 is approximately one-half the width d1 and d2 of the bases of the flanges l2 and digging plates 6. The protruding portions 42 are also bent slightly so that they slant towards the tips of the flukes 4. Typically the angle A between the protruding portions 42 and the side plates 22 is between and This angle may vary over a fairly wide range; for example it could be made as great as and could be made much smaller (e.g. about 40). The angle A should be less than 90 for maximum efficiency (as will be explained) and an angle of between 70 and 75 has been found to perform efficiently.

The protruding portions 42 of the base plate can of course be continuously curved, and in fact the entire base plate 36 can be continuously curvedv In this event the angle between the protruding portions and the side plates means the angle between the side plate and a chord extending from the juncture of the side plate and its associated protruding portion to the tip of such protruding portion.

In order to increase the amount of side-to-side movement available for the shank 26 each side plate 22 contains a slot 44 of width slightly greater than the diameter of the shaft 30 of the shank.

Once the shank 26 enters one of the slots 44, any side-toside forces on the shank will be absorbed in part by the side plates 22, rather than solely by the bushing 28, thus increasing the permissible side-to-side forces that can be exerted on the shank (e.g. when levering the anchor out of a bottom in which it is caught).

When the anchor is used, it is dropped from a boat to the bottom 46 (FIG. 9) underlying the water. When the anchor is initially dropped, it may typically assume the position shown in FIG. 9, with the digging plates lying horizontally or tilted slightly downwardly. The lowermost protruding portion of the base plate, indicated at 420 in FIG. 9, digs into a soft bottom but its slope relative to the side plate 220 will often prevent it from burying itself and it may therefore raise the base of the anchor slightly, tilting the tips of the flukes 4 downwardly.

As the boat to which the anchor is attached begins to drift, the anchor is dragged in the direction of arrow B, and mud and dirt collects in the space marked x between the bottom protruding portion 420 and the bottom side plate 220. The accumulated mud and dirt forces the base of the anchor upwardly, tilting the points of the flukes downwardly so that they will bury themselves. As the anchor is dragged, the broad conerging flanges 12 funnel dirt into the box at the anchor base, icreasing resistance to dragging. The anchor will typically ury itselfin the bottom 46 to the position shown in FIG. 10.

When the anchor is to be pulled upwardly, the anchor line 4 is pulled in. The anchor usually remains buried until the oat is virtually over it, at which time the anchor line 34 exends upwardly. The tip of the bottom protruding portion 420 hen acts as a fulcrum about which the anchor rotates, so that he anchor can fairly easily be pried out of the bottom.

The anchor described contains several features which make iossible a strong lightweight structure with good holding lower and which will bury itself quickly in a soft bottom. imong these features are the protruding portions 42 of the iase plate, which trap dirt efficiently in the acute or right .ngle formed between themselves and the side plates to tilt the lukes downwardly; the strong box structure at the base of the inchor, which adds great strength and also acts as a trap to :atch bottom sediments and increase resistance to dragging and the broad flanges 12 which direct bottom sediments into he box structure and also serve double duty as part of the box tructure.

Since the flanges l2 taper progressively towards their tips, he box structure at the base of the anchor widens laterally 'rom its open to its closed end, helping to retain mud and dirt unnelled therein.

TABLE I Typical dimensions for a 133 5 pound anchor of Mo inch steel plate] Sim, Dimension inches 11 (width of base of fla e 12) 4 12 (width oi base 0! dl ng plate 6). 4 l3 (height of digging p to B). 14 14 (height of flanges 12) l7 15 (he! ht oi side plate 22) 5 16 (vi th 0! side plate 22) 4 t? e hoibase p1ete36 8% t8 (wl th of base plate 36) 4 19 (length of protruding portion 42) 4 Length of shank shalt 13 Length of shank ring 32 beyond shank shot 6% Dlameter of shank shaft 30 1 ,4 Length of shank bushing 28 2% Outer diameter of shank bushing 28 1 1% inner diameter of shank bushing 28 003 Length of stock 2 18 Diameter of stock 2 Width of slot 44 in side plate 22 I Height of slot 44 in side plate 22 2% Further concerning dimensions, it is found that the anchor functions most efficiently when the angle between the shank Z6 and the digging plates 6 (this angle is marked C in FIG. 9) is in the range between and 50. in this range, the anchor is most effective in collecting sediments and digging itself into the bottom. An angle of 33 has been found particularly effective for the [3% pound anchor described. The angle is adiusted by controlling the length of the slots 44 in the side plates 22.

lclaim:

I. An anchor comprising:

a. a stock;

b. a pair of flukes comprising:

i. a pair of digging plates having base portions fixed to said stock and extending from said stock in a common plane with said stock, said digging plates having pointed tips;

ii. a pair of flanges extending along opposed inside edges of said digging plates at right angles thereto, said flanges having enlarged bases and tapering towards said tips of said digging plates to define pointed tips for said flukes;

c. a pair of side plates joining the bases of said flanges to form a box structure having an open end facing the tips of said flukes, said stock extending through said box structure;

. a shank pivotally connected to said stock at a location within said box structure and protruding from said box structure in a direction towards the tips of said flukes; and

e. a base plate closing the end of said box structure opposite said open end, said base plate having protruding portions extending substantially beyond said side plates, so that when said anchor is dragged along a relatively soft bottom, dirt will collect between a said side plate and the protruding portion of said base plate adjacent said side plate and will tilt the tips of said flukes downwardly to bury said anchor.

2. An anchor according to claim 1 wherein the protruding portions of said base plate slant towards the tips of said flukes, to reduce the tendency of the lowermost of said protruding portions to penetrate into a soft bottom when said anchor is initially deposited on a bottom, and to facilitate entrapment of dirt between said lowermost protruding base plate portion and its adjacent side plate.

3. An anchor according to claim 1 wherein the angle between said protruding base plate portions and said side plates is in the range between and 40.

4. An anchor according to claim 2 wherein the lateral width of said flanges at their enlarged bases is approximately the same as the width of said digging plates adjacent their connection with said stock, said flanges converging inwardly toward each other from their tips to their bases to funnel dirt into said box structure.

5. An anchor according to claim 4 wherein said flanges taper progressively from their enlarged bases to their tips, so that said box structure widens laterally from its open to its closed end.

6. An anchor according to claim 5 wherein each side plate includes, at its edge located between said flanges and opposite the edge connected to said base plate, a slot of width slightly greater than the diameter of said shank, to accommodate said shank as it moves from side to side.

7. An anchor according to claim 6 wherein the length of said slots is such that when said shank has moved to its limit within either slot, the angle between said shank and said digging plates is in the range between 20 and 50".

8. An anchor comprising:

a. a stock;

b. a pair of flukes comprising:

i. a pair of digging plates having base portions fixed to said stock and extending from said stock in a common plane with said stock towards pointed tips, the inside edges of said digging plates diverging towards said tips;

ii. a pair of flanges extending along said opposed inside edges of said digging plates at right angles to said digging plates, said flanges having enlarged bases extending beyond the bases of said digging plates and beyond said stock, the ends of said bases being convexly curved and being approximately equal in width to the width of the bases of said digging plates, said stock passing through said enlarged bases of said flanges, said flanges tapering progressively from their bases towards the tips of said digging plates to define pointed tips for said flukes;

c. a pair of side plates joining the enlarged bases of said flanges to form a box structure having an open end facing the tips of said flukes;

. a shank pivotally connected to said stock between said side plates and protruding from said box structure in a direction towards the tips of said flukes; and

e. a base plate closing the end of said box structure opposite said open end, said base plate curving around said ends of said bases and having protruding portions extending beyond said side plates by an extent approximately equal to one-half the width of said ends of said enlarged bases of said flanges, said protruding portions slanting slightly towards said tips of said flukes. 

